True. Doing that wouldn't be easy right now.

However, it doesn't necessarily need to get back to Earth. If we have power up in space, it gets much easier to run mining operations on asteroids, the moon etc. As soon as we have both power and minerals, we can also start putting factories in orbit instead of on Earth, reducing energy need down here.

The stuff those factories produce can be dropped down to Earth, OR we use that stuff in space to build even more infrastructure. In fact, at this point it becomes feasible to build really nice space stations that people can go live on if they want. Eventually, we'd even have the production capacity to build O'Neill Cylinders.

Now we can just continue building and mining in space, while developing or preserving Earth as we like.